Pancake window display system employing one or more switchable holographic optical elements

An optical system including one or more switchable holographic optical elements is described for use with a pancake window display system. Each of the switchable holographic optical elements of the optical system operates between active and inactive states in accordance with control signals provided by a control logic circuit. In the active state, each switchable holographic optical element operates to reflect and collimate a narrow band of incident light thereon. In the inactive state, the switchable holographic optical element operates to transmit a substantial portion of light thereon without substantial alteration.